By Trevor Hunnicutt

PELLA, Iowa, Jan 30 - Democratic U.S. presidential candidate Joe Biden on Thursday said Bernie Sanders "regrets" some of his views on gun policy, remarks highlighting a possible line of attack on a rival for their party's presidential nomination.

"Bernie has made his verbal amends for his record," Biden said in response to a question from a reporter between campaign stops on a bus tour of Iowa.

Biden, fighting a close race against Sanders and others in the Democratic party's first presidential nominating contest on Monday, then spotlighted elements of the senator's record.

Specifically, Biden pointed out Sanders' voting against the 1993 Brady Bill that imposed mandatory background checks and waiting periods for gun purchases. He also mentioned Sanders' support for a 2005 federal law that shielded gun manufacturers, distributors and dealers from civil liability for mass shootings.

"I think he regrets having done that. It was in a campaign in Vermont - a tough race for U.S. Senate," Biden said. "I think he's changed his mind, so I take him at his word."

Sanders campaign manager Faiz Shakir responded that "last-minute, cheap barbs of desperation aren't a good look for a candidate who proclaims his desire to unite the party."

Sanders has said his views on gun control have changed, along with the American public, in response to what he has called incidents of "terrible, frightening gun violence" in recent years.

Biden also offered other assessments of the contrast he offers with other Democrats ahead of Monday's caucus, saying he has won more than the few thousand votes, a reference to former South Bend, Indiana mayor Pete Buttigieg.

Buttigieg, who is also seeking the nomination, told Iowans earlier on Thursday that he had heard "Vice President Biden saying that this is no time to take a risk on someone new" but that "history has shown us that the biggest risk we could take with a very important election coming up is to look to the same Washington playbook and recycle the same arguments."

Biden also said he knows how he will pay for his healthcare plan. Sanders has not said exactly how his Medicare for All plans would be funded, but has set out options that could fund some of the cost, including a 7.5% payroll tax paid by employers and a 4% tax on household earnings over $29,000.

(Reporting by Trevor Hunnicutt; Additional reporting by Simon Lewis in Washington. Editing by Gerry Doyle)